I’ve heard too many bad stories about hard undercoating including mechanics who won’t even work on undercoated vehicles due to sensors and connectors all sealed up with that stuff.
I watched a lot of videos and decided to use Fluid Film to protect the underside of my new 2500.
The truck is a moose compared to my last truck, a 95 Ram 1500. I kept my Dart as a beater since many parking lots and dense suburban environments are not fun with a 3/4 ton crew cab! The front of my truck sticks out close to 2’ from the parking spot in my works parking garage even with the bumper inches from the back wall. That’s with a 6’4 bed, if I had an 8’ bed and left a hitch installed someone would be tapping me on the shoulder telling me I’m blocking too much of the aisle and can’t park my truck there!